Joe Strummer said that he got the idea for the song when he was thinking about terrorists, and how they probably enjoy reading about their killings as much as movie stars like seeing their films reviewed.[3] While Topper Headon mimics the sound of gangster movie shootings with quick snare hits and the guitars are full of distortion and feedback, Strummer's sarcastic lyrics (I'm cutting out your picture from page one/I'm gonna get a jacket just like yours/And give my false support to your cause/Whatever you want, you're gonna get it!) condemn rather than condone violence: at the end of the song he sings, If death comes so cheap/Then the same goes for life!
In the liner notes of the Singles Box, Carl Barat (former frontman of Dirty Pretty Things and The Libertines), says that "Tommy Gun" was important for music at the time because it let people know what was going on in the world—it talked about real issues. He says,
^Wyman, Bill (11 October 2017). "All 139 the Clash Songs, Ranked From Worst to Best". Vulture. New York. Retrieved 14 March 2023. An interesting early pop-punk artifact however. Put out for some reason as the B-side of the "Tommy Gun" single in 1978, and later collected on Super Black Market Clash.